You know, there's a secret I could tell you. It's a bit dangerous, but hey, danger is fun, right? Okay, okay, relax. I'll just tell you the secret. Bloody Mary exists in all mirrors at once. There's a Bloody Mary in each mirror.
Why am I telling you this? Because, if you place two mirrors together, facing each other, about 3–4 feet across... They're thousands of mirrors reflected in both of the mirrors, correct? Good. Now follow the procedure of calling upon Bloody Mary. As soon as you successfully summon her, duck and move out of the frames of the mirrors. Do you remember what I said earlier, about all the Bloody Marys and mirrors?
If done correctly, they will kill each other, and you will have Bloody Mary free mirrors. But why anyone would do this is beyond me, as Bloody Mary doesn't even exist.
Just a thought, what if the mirrors were too far apart, and Bloody Mary existed?
Oh dear.